Purification and some characterization of an extracellular ?-amylase from a thermotolerant Bacillus subtilis
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Tarih
2003
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Extracellular alpha-amylase from Bacillus subtilis was purified by ion-exchange chromatography and gel filtration. The molecular weight was determined to be 48.000. Various metal ions inhibited alpha-amylase activity even at low concentrations (5 mM). Ca2+, Ba2+, m,(2+) and Ni2+ were mild inhibitors, whereas Zn2+, Fe2+, Pb2+, H2+ Mg2+, Cd2+ and Cu2+ were potent inhibitors. The activity of the enzyme was reduced by Ca2+ at high concentrations but increased at 2.5 mM. Ethylenediaminetetraacedicacid (EDTA) also affected the enzyme activity even when compared with Ca2+ ions at low concentrations. Calcium and EDTA showed dose-dependent inhibition. Different enzyme solution containing Ca2+, Ba2+ and Mg2+ (2.5 mM and 10 mM) was added 2.5 mM EDTA and enzyme activity increased at 10 mM metal ions concentrations. The K-m and V-max values for alpha-amylase were found to be 2.2 x 10(-4) g mL(-1) and 0.020 U mL(-1), 2.91 x 10(-4) g mL(-1) and 0.016 U mL(-1), 4.04 x 10(-4) g mL(-1) and 0.021 U mL(-1) for starch, amylose and glycogen. respectively.
Açıklama
Anahtar Kelimeler
Bacillus Subtilis, Alpha-Amylase Production, Metal Ions
Kaynak
Annals of Microbiology
WoS Q Değeri
Q4
Scopus Q Değeri
Q2
Cilt
53
Sayı
3
